What are the different types of army units such as platoons in world war 2?

Answer 1

This varied from army to army.

The US Army in WWII was "triangular". This meant that at every level a commander had available three maneuver units plus a support unit.

The basic infantry formation was the rifle squad, usually twelve men in the US forces, led by a sergeant. Four squads made a rifle platoon. Three of these were rifle squads, and one was a "weapons" squad, with machine guns and 60mm mortars.

Four platoons made a rifle company. Three rifle platoons plus a weapons platoon, with more machine guns and mortars.

Four companies made a battalion - three rifle companies plus a heavy weapons company.

Three battalions made a regiment, and three regiments made an infantry division. Each infantry division also had four artillery battalions, so a battalion of artillery could be attached to each infantry regiment to back up its three infantry battalions, preserving the triangular approach to tactics.

The three maneuver units allowed a commander to utilize the only tactic taught to the massive number of young men who had to be trained as infantry officers: the holding attack. The commander could use one or two units to pin the enemy down, and then use the other one or two to try to get around the enemy position, to attack them in the flank (from the side) or the rear.

Two or more infantry divisions, plus an armored division, usually, in Europe, made an Army Corps.

Two or more corps made a Field Army. Two or more Field Armies made an Army Group.